Selfie JVM Snapshot Garbage Collection is overly zealous when using multiple test suites in gradle

In a project I was using a separate integrationTest source set with the JVM Test Suite approach recommended by Gradle link to instructions.

When done this way, the integration test sources will be in src/integrationTest instead of src/test. The classes in src/test will not be on the classpath of the integration tests.

When running Selfie with JUnit5, the current garbage collection logic is hardcoded to only look for *.ss files in src/test/ and performs a Class.forName(...) to see if that test still exists and has tests that match the snapshot. If it doesn't find a match, it deletes the file.

Since the unit tests are invisible on the integrationTest classpath, though, Class.forName(...) throws a ClassNotFoundException so selfie assumes this is a stale file and deletes. As a consequence, all the unit test snapshots are deleted when running the integrationTest task.

Is there some way to get the correct source root from Junit or something like that to avoid deleting unmanaged files?

A reproducer of the described issue can be found here with instructions in the README https://github.com/aelfric/selfie-bug-report-reproducer

I think you can fix this by providing a SelfieSettings class which implements this:

selfie/jvm/selfie-runner-junit5/src/main/kotlin/com/diffplug/selfie/junit5/SelfieSettingsAPI.kt

Lines 82 to 98 in 61526f5

    
             /** 
        
              * If Selfie should look for test sourcecode in places other than the rootFolder, you can specify 
        
              * them here. Selfie will not store snapshots in these folders. 
        
              */ 
        
             open val otherSourceRoots: List<File> 
        
               get() { 
        
                 return buildList { 
        
                   val rootDir = rootFolder 
        
                   val userDir = File(System.getProperty("user.dir")) 
        
                   for (standardDir in STANDARD_DIRS) { 
        
                     val candidate = userDir.resolve(standardDir) 
        
                     if (candidate.isDirectory && candidate != rootDir) { 
        
                       add(candidate) 
        
                     } 
        
                   } 
        
                 } 
        
               }

But very possible I'm misremembering. Happy to take a PR which makes this easier.

Yes, the SelfieSettings approach works, although I had to override rootFolder rather than otherSourceRoots to avoid deleting the unit test snapshots. I started reviewing the junit listener code in a bit more detail. I'm not sure if there is any sort of quick fix to PR but I'll keep looking.

Navigation Menu

Repository navigation

Selfie JVM Snapshot Garbage Collection is overly zealous when using multiple test suites in gradle #574

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

	/**
	* If Selfie should look for test sourcecode in places other than the rootFolder, you can specify
	* them here. Selfie will not store snapshots in these folders.
	*/
	open val otherSourceRoots: List<File>
	get() {
	return buildList {
	val rootDir = rootFolder
	val userDir = File(System.getProperty("user.dir"))
	for (standardDir in STANDARD_DIRS) {
	val candidate = userDir.resolve(standardDir)
	if (candidate.isDirectory && candidate != rootDir) {
	add(candidate)
	}
	}
	}
	}

Selfie JVM Snapshot Garbage Collection is overly zealous when using multiple test suites in gradle #574

Description

Activity

nedtwigg commented on May 6, 2026

aelfric commented on May 7, 2026

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions